Copper Wire Research Articles

Achieving extraordinary strength and conductivity in copper wire by constructing highly consistent hard texture and ultra-high aspect ratio

Simultaneously improving the strength and electrical conductivity of conducting metallic materials is of great significance, but it still remains a key challenge as the two properties are often mutually exclusive. In this study, we demonstrate a “<111> oriented fibrous grains with ultra-high aspect ratio” strategy for breaking such a conflict in Cu wire, which relies on the distinctive spatial distribution of grain boundaries and the highly consistent hard orientation to play their respective roles in suffering loading and conducting, thereby enabling a separate optimization of both strength and electrical conductivity. Therefore, a processing route was designed, involving directional solidification followed by large drawing deformation, to successfully construct fibrous grains with an ultra-high aspect ratio in 596.7 and ultra-high <111> texture proportion over 97%, which achieves Cu wire with a remarkable combination of yield strength in 482.3 MPa and electrical conductivity in 101.63% IACS. Finally, the mechanisms for high strength and high electrical conductivity were quantitatively discussed.

Study on the Technology and Properties of Green Laser Sintering Nano-Copper Paste Ink.

With the rapid development of integrated circuits, glass substrates are frequently utilized for prototyping various functional electronic circuits due to their superior stability, transparency, and signal integrity. In this experiment, copper wire was printed on a glass substrate using inkjet printing, and the electronic circuit was sintered through laser irradiation with a 532 nm continuous green laser. The relationship between resistivity and microstructure was analyzed after laser sintering at different intensities, scanning speeds, and iterations. The experimental results indicate that the conductivity of the sintered lines initially increases and then decreases with an increase in laser power and scanning speed. At the same power level, multiple sintering runs at a lower scanning speed pose a risk of increased porosity leading to reduced conductivity. Conversely, when the scanning speed exceeds the optimal sintering speed, multiple sintering runs have minimal impact on porosity and conductivity without altering the power.

Joining thin copper wire and copper busbar by remote laser welding for electric motor assembly: Impact of welding parameters and pre-welding surface treatment

Joining thin copper wire and copper busbar by remote laser welding for electric motor assembly: Impact of welding parameters and pre-welding surface treatment

THE APPLICATION OF SWAN IDEA SOURCE ON BRIDAL FASHION

Swans are the most loyal animals that only mate once in a lifetime. The purpose of this research is to find out the process of making and the finished result of bridal fashion with a swan as the source of the idea. This research method uses a three-stage design process approach. This method consists of three stages of research: problem definition and research, creative exploration and implementation. The design direction was determined in the initial stage, and in the second stage, a moodboard was made. The implementation stage involves applying a swan feather and manipulating fabric decoration as the centre of attention on the bridal outfit. The process of manipulating fabric starts with preparing copper wire, segment fabric and brocade fabric, then cutting to form strands of swan feathers and sewn with balut stitch on all sides to unite the three materials. The results of this research show bridal fashion with feather-shaped manipulating fabric decoration, with two designs of men's and women's bridal fashion. The final result is the style of Muslim clothing, according to the provisions of Islamic law, intended to cover parts of the body that are inappropriate to be shown to the public. The primary material is tille sequins and satin maxmara lining with the appropriate size, but it does not show the shape of the woman's body so that it can be worn for Muslim women wearing hijab.

How does the period of a pendulum vary with the number of strings?

This article serves as an extension of analysis of a simple pendulum, a typical example of simple harmonic motion and a common topic in high school physics syllabus. Since the analysis of a simple pendulum ignores the mass of the string in order to model the system as a point mass, a more complex pendulum system consisting of heavy strings and a pendulum bob is explored in this article. Based on theoretical analysis of the model, a relationship between the number of strings and the period of the pendulum is investigated. An experiment was also conducted on a pendulum system using copper wire, a glass bob, a stand, clamps, a clip and a stopwatch. To obtain more accurate results, time taken for five periods was measured three times for each number of strings. A graph is drawn based on data acquired from the experiment and the theoretically deduced relationship is therefore verified. Further study of the general expression for the period of an object that cannot be modelled as a point mass oscillating about a fixed axis is involved. Application of the principle that a change in the position of the center of mass of a pendulum causes a change in its period in Big Ben is also discussed along with a brief introduction of its pendulum structure.

Characteristics of Conductive Paints and Tapes for Interactive Murals

This paper analyzes a collection of conductive paints and tapes. We describe and compare their electrical conductivity, durability, appearance, and cost. We investigate different means of connecting these materials to each other and other electronic components-including connection via solder, conductive epoxy, conductive adhesives, and metal mechanical fasteners. We explore different means of insulating and protecting materials and provide the results of a range of durability tests. The results are discussed in the context of the development of interactive murals-large outdoor interactive surfaces that are intended to function for years. We identify two conductive paints, CuPro-Cote and Silver/Copper Super Shield, and two conductive tapes, Copper and Tin that are highly conductive, stable across most of our testing conditions and, we believe, suitable for interactive murals.

Effects of water chemistry on corrosion and plugging in the copper heat exchangers of water-cooled generators in power plants

Corrosion and plugging of hollow copper conductors in water-cooled generators can cause system failures, such as flow restrictions and forced unit outages. Although both neutral water chemistry (NWC) and slightly alkaline water chemistry (SAWC) have been proposed as solutions, field operations show that NWC frequently suffers from system failures, while SAWC demonstrates high reliability. The scientific basis for this phenomenon has not been well understood. In this paper, the thermodynamics of NWC and SAWC were established to compare their tendencies toward copper corrosion and plugging. SAWC keeps copper in a stable CuO passivation region, exhibiting a superior buffer capacity against CO2 inleakage and the temperature rise of the cooling water. This buffer capacity is further enhanced by increasing the degree of the slight-alkalization. Under the SAWC with a pH value of 9.0 at 298.15 K, the concentration of the dissolved copper species is extremely low, and the positive temperature coefficient of CuO solubility prevents the accumulation of copper corrosion products in high-temperature regions. In contrast, NWC is susceptible to corrosion and plugging due to its poor buffer capacity. This study provides new insights into the effects of water chemistry on copper corrosion and plugging from a thermodynamic perspective, offering a sound theoretical basis for field operations.

A low‐profile, wideband, circularly polarized, slotted, U‐shaped textile antenna for W‐BAN applications

AbstractWe propose a compact, wideband, U‐shaped, circularly polarized textile antenna (UCPTA) resonating at 2.45 GHz for wireless body area network (W‐BAN) applications. The radiator of the antenna is printed on the top of the substrate (size of mm3; ) and has a full ground plane on the other side. The proposed antenna's substrate consists of a single layer of denim (), and conductive copper tape was used to fabricate the patch. The antenna has a low‐profile design that is suitable for wearable applications. A small slot was introduced at the center of the U‐shaped patch to enhance the 3 dB axial ratio bandwidth (ARBW) up to 55.17%. The proposed antenna radiates with a 10 dB return loss (RL), impedance bandwidth (IBW) of 64.40%, and a simulated gain of 5.1 dBi. The wearable textile antenna with broadside radiation response is appropriate for off‐body communications. The prototype of UCPTA is fabricated for experimental validation. The measured results for the fabricated antenna were in good agreement with the simulated results. Further, it has been demonstrated that the antenna's performance is stable during structural deformation and human body loading. This textile antenna covers an ARBW in the frequency band of 2.1 GHz–3.72 GHz and has a broad IBW (2 GHz–3.9 GHz) for LTE (2.17 GHz), MBAN (2.360 GHz–2.4 GHz), WPAN (2.395 GHz–2.4 GHz), and WLAN (2.4 GHz–2.482 GHz) applications.

Analysis of the twisting effect in an equal-channel stepped die and drawing on copper wire mechanical properties

Analysis of the twisting effect in an equal-channel stepped die and drawing on copper wire mechanical properties

Synergizing intelligent signal processing with wavelength-division multiplexing for enhanced efficiency and speed in photonic network communications

Abstract The explosive growth of worldwide mobile data traffic seeks innovations in communication technology to cater to the mounting need for rapid connectivity, high-capacity connections. The mainstreaming of 5G technologies for communication is a dramatic step towards meeting the aforementioned goals, with the ability for reshaping IoT (Internet of things), D2D (device-to-Device) communications, and the smart grids. This work conveys an in-depth study of the fundamental innovations that underlie 5G, including full-duplex distribution, huge multiple-input-multiple-output, ultra-dense connections, the phenomenon of beamforming and millimeter-wave approaches. A special emphasis is focused on the integration of photonic technologies, or microwave photonics, which serves as a critical multidisciplinary study topic. Optical fibers, with their tremendous bandwidth and capacity, have been determined as the best medium for backhaul and fronthaul amenities, outpacing conventional copper cables to accommodate tiny cells and next-generation networks. The synergy between optical and wireless access technologies is analyzed with the emphasis on the central role of wavelength-division multiplexing (WDM) for improving network efficiency and speed. The investigation additionally explores the possibility of intelligent signal processing methods combined with WDM to optimize photonic network communications. The mingling of these technologies anticipates producing unrivaled levels of performance, rupturing the path for an additional intelligent, interconnected era.

Printable and filament-drawable PDMS based adhesive assisted manufacturing of highly conductive copper micro-patterns

Manufacturing of copper micro-patterns is crucial in electronics for its utilization as high conductivity transparent conductive films (TCFs) and circuits. In the preparation process of current TCFs, a plethora of materials have emerged that can replace traditional indium tin oxide (ITO). However, even for the most promising metal-based nanowire materials, there are issues such as high cost, complex welding, and high contact resistance. To address these problems, this paper proposes a printable and filament-drawable polydimethylsiloxane (PDMS)-based adhesive, which, through a novel additive patterning technology, efficiently and economically manufactures self-welding copper micro-meshes and circuits. The adhesive can be processed into micro-patterns through printing and filament drawing, on which ionic Ag can be in situ reduced and anchored, thereby eliminating the need for tedious pre- and post-treatment steps. The fully exposed Ag particles dramatically minimize the usage of precious metal catalyst, thus efficiently catalyzing electroless copper deposition (ECD) reaction. Highly conductive (1.03 × 107 S m−1) copper circuits can be fabricated on the printed adhesive patterns, exhibiting versatile applicability to diverse substrates. Highly precise copper micro-meshes (∼50 μm) can be fabricated on the filament networks drawn by the adhesive. The copper meshes undergo complete self-welding at junctions during the ECD process, thus exhibiting ultra-low square resistance of 0.45 Ω sq−1 while maintaining a high transmittance of 82.2 %. This is far superior to most of TCFs in published literature.

Comparative study on upward flame spread interactions and heat transfer over two parallel wires with various spacing distances in open space and vertical channel

Most previous work focused on the flame spread interactions and heat transfer over two parallel wires in open space, but few studies considered the vertical channel effects. Experiments were carried out to investigate the influence of vertical channel on the flame spread interactions and heat transfer over two parallel wires. Two types of polyethylene-insulated copper wires were used with spacing distance ranging from 0 mm to 52 mm. Whether for open space or vertical channel, four typical regimes of upward flame interactions are observed as a function of spacing distance, but the range of these regimes is affected by the vertical channel. For open space and vertical channel, the flame width, flame length and flame spread rate rise first and then drop, but these parameters for vertical channel are larger than that for open space due to the enhanced induced flow and the heat transfer. A heat transfer model is established for upward flame spread over two parallel wires taking the effects of spacing distance and vertical channel, in which the radiation from flame is considered, as well as the difference between the solid-phase and gas-phase heating lengths. The flame heat feedback is the dominant mechanism for upward flame spread over two parallel wires, and it for vertical channel is larger than that for open space.

Improved thermal conductivity of high‐density polyethylene by incorporating hybrid fillers of copper powders and silicon carbide whiskers

AbstractIn this paper, highly electrically and thermally conductive copper powders (Cu) and electrically insulative yet thermally conductive silicon carbide whiskers (SiCw) were selected as functional fillers and high‐density polyethylene (HDPE) was used as the matrix to prepare thermal conductive composites. By controlling the amount of Cu at 30 vol% which is below percolation threshold, the volume resistivity of the composites is maintained above 1014 Ω cm. The results showed that SiCws entered the area which was not occupied by Cu particles and they played a bridging effect among Cu particles, thereby promoting the formation of intact thermal conductive pathways that contributed to improving the thermal conductivity of corresponding composites. The combination of SiCw:Cu = 3:1 at a filler content of 30 vol% resulted in a thermal conductivity as high as 1.921 W/mK, which is 380% higher than pure HDPE.

Development of high impact toughness Cu/ODS-Cu joints using HIP bonding process for the preparation of W/Cu/ODS-Cu monoblock divertor

Compared to CuCrZr, oxide dispersion strengthened copper alloy (ODS-Cu) exhibits higher stability of properties under irradiation and exposure to elevated temperatures, demonstrating broad application prospects in divertor components. Oxygen-free high thermal conductivity copper (Cu-OFHC) has been frequently employed as an interlayer between W and Cu-based alloy in the fabrication of W/Cu divertor components. This study investigates the effect of joining temperature together with the addition of a Ni interlayer on the interface microstructure and mechanical properties of the Cu-OFHC/ODS-Cu joints. As the joining temperature increased from 680 ℃ to 900 ℃, the interface bonding ratio of the Cu-OFHC/ODS-Cu joints improved from 40.4% to 95.8%, and the impact toughness increased from 23.4 J/cm2 to 133.1 J/cm2. With the addition of a Ni interlayer, the interface bonding ratio increased from 40.4% to 90.3%, and the impact toughness improved from 23.4 J/cm2 to 122.5 J/cm2. Increasing the joining temperature or adding a Ni interlayer effectively reduced interfacial voids, enhanced the interface bonding ratio, and consequently improved the impact toughness of Cu-OFHC/ODS-Cu joints. Then, the W/Cu/ODS-Cu monoblock mock-ups with good interfacial bonding were successfully fabricated under two conditions: at a joining temperature of 900 ℃ without an interlayer and at 680 ℃ with a Ni interlayer. These results provide a fundamental understanding for achieving high-quality Cu-OFHC/ODS-Cu joints and offer technical support for the engineering preparation of W/Cu/ODS-Cu components in future fusion devices.

Dynamic phase change materials with extended surfaces

Phase change materials (PCMs) present opportunities for efficient thermal management due to their high latent heat of melting. However, a fundamental challenge for PCM cooling is the presence of a growing liquid layer of relatively low thermal conductivity melted PCM that limits heat transfer. Dynamic phase change material (dynPCM) uses an applied pressure to pump away the melt layer and achieve a thin liquid layer, ensuring high heat transfer for extended periods. This paper investigates heat transfer during dynPCM cooling when the heated surface has extended features made from high thermal conductivity copper (Cu). Using experiments and finite element simulations, we investigate the heat transfer performance of dynPCM paraffin wax on finned Cu surfaces. A total of 102 transient temperature measurements characterize the performance of dynPCM with extended surfaces and compare the performance with other cooling methods including hybrid PCM and air cooling. The study examines the effects of fin geometry, applied power (20–65 W), and pressure (0.97–12.5 kPa). For dynPCM on a finned surface and a heating power of 65 W, the thermal conductance is 0.45 W/cm2-K, compared to 0.22 W/cm2-K for dynPCM on a flat surface and 0.10 W/cm2-K for hybrid PCM. The heat transfer is highest at the fin tips where the melt layer is thinnest, providing valuable design guidelines for future high performance dynPCM cooling technologies.

Effect of wire diameter compression ratio on drawing deformation of micro copper wire

A crystal plasticity finite element model was developed for the drawing deformation of pure copper micro wire, based on rate-dependent crystal plasticity theory. The impact of wire diameter compression ratio on the micro-mechanical deformation behavior during the wire drawing process was investigated. Results indicate that the internal deformation and slip of the drawn wire are unevenly distributed, forming distinct slip and non-slip zones. Additionally, horizontal strain concentration bands develop within the drawn wire. As the wire diameter compression ratio increases, the strength of the slip systems and the extent of slip zones inside the deformation zone also increase. However, the fluctuating stress state, induced by contact pressure and frictional stress, results in a rough and uneven wire surface and diminishes the stability of the drawing process.

Crack-Resistant Si-C Hybrid Microspheres for High-Performance Lithium-Ion Battery Anodes.

To effectively solve the challenges of rapid capacity decay and electrode crushing of silicon-carbon (Si-C) anodes, it is crucial to carefully optimize the structure of Si-C active materials and enhance their electron/ion transport dynamic in the electrode. Herein, a unique hybrid structure microsphere of Si/C/CNTs/Cu with surface wrinkles is prepared through a simple ultrasonic atomization pyrolysis and calcination method. Low-cost nanoscale Si waste is embedded into the pyrolysis carbon matrix, cleverly combined with the flexible electrical conductivity carbon nanotubes (CNTs) and copper (Cu) particles, enhancing both the crack resistance and transport kinetics of the entire electrode material. Remarkably, as a lithium-ion battery anode, the fabricated Si/C/CNTs/Cu electrode exhibits stable cycling for up to 2300 cycles even at a current of 2.0 A g-1, retaining a capacity of ≈700 mAh g-1, with a retention rate of 100% compared to the cycling started at a current of 2.0 A g-1. Additionally, when paired with an NCM523 cathode, the full cell exhibits a capacity of 135 mAh g-1 after 100 cycles at 1.0C. Therefore, this synthesis strategy provides insights into the design of long-life, practical anode electrode materials with micro/nano-spherical hybrid structures.

Design and thermal simulation of the front-end module for STARLIGHT

This paper presents a front-end module emulator for SemiconducTor Array detectoR with Large dynamIc ranGe and cHarge inTegrating readout (STARLIGHT), a versatile hybrid silicon pixel detector with a high frame rate (≥10kHz) and serving as the first charge-integrating pixel detector for XFEL in China. The detector is intended for operation in a vacuum environment, with the front-end module generating a thermal power of up to 5.443 mW/mm2, presenting a significant challenge for thermal management. To assess the thermal management capabilities of the mechanical and PCB designs for the project, a thermal emulator was developed to replicate the heat generated by the ASIC. This was particularly crucial during the early stages of the project when the ASIC was not yet available, achieved by placing copper wires on the PCB. Subsequent thermal simulations were conducted and compared with the results obtained from the thermal emulator. The comparison shows that the experimental results are very close to the thermal simulation results, validating the thermal performance of the STARLIGHT front-end modules. These endeavors not only provide validation but also offer valuable insights to ensure the thermal efficiency of the STARLIGHT front-end modules.

Room temperature compressed air-stable conductive copper films for flexible electronics

The state-of-the-art technology of fabricating printed copper electronics is focussed largely on thermal sintering restricting transition towards heat sensitive flexible substrates. Herein we report a pioneering technology which eliminates the need for conventional sintering. Biopolymer-stabilised copper particles are prepared such that they can be compressed at room temperature to generate air-stable films with very low resistivities (2.05 – 2.33 × 10−8 Ω m at 20 °C). A linear positive correlation of resistivity with temperature verifies excellent metallic character and electron microscopy confirms the formation of films with low porosity (< 4.6%). An aqueous ink formulation is used to fabricate conductive patterns on filter paper, first using a fountain/dip pen and then printing to deposit more defined patterns (R < 2 Ω). The remarkable conductivity and stability of the films, coupled with the sustainability of the approach could precipitate a paradigm-shift in the use of copper inks for printable electronics.

Analysis of a passive vibration damper for high-speed superconducting magnetic bearings

Superconducting magnetic bearings (SMB) based on a combination of high temperature superconductors and permanent magnets enable the realization of self-stabilized high-speed devices with significantly reduced friction. However, external vibration might couple in the bearing resulting in large amplitude oscillations due to a resonance case. A dedicated eddy current damper (ECD) might be used to eliminate these oscillations for a stable operation. The influence of such damping elements was studied for a frictionless SMB twisting system designed to speed up the conventional ring spinning process. Therefore, conductive copper rings with different thicknesses were implemented at different positions into the bearing setup as ECD. Afterward, the SMB setup was analyzed during acceleration using an array of laser distance sensors to record the displacement of the levitating permanent magnet ring in radial and axial direction, respectively. Simultaneously, a numerical model was developed to investigate the influence of the ECDs on the dynamic and static behavior of the SMB in more detail. It was shown that the simulated damping coefficients are in good agreement with the measured values, which allows further optimization of the ECD with the developed numerical model.